A fulacht fia is a prehistoric cooking site, typically consisting of a horseshoe-shaped mound of heat-cracked stone beside a trough. The stones were heated in a fire, then dropped into the water-filled trough to bring it to the boil; repeated use left accumulations of shattered, blackened material that survive long after everything else has vanished.

This particular site came to light not through deliberate excavation but through the digging of a drain, which is, as it happens, a surprisingly common way for fulachtaí fia to surface. Their low, waterlogged settings, chosen in prehistory precisely because water was readily available, make them vulnerable to agricultural drainage work, and it is often a farmer or a labourer rather than an archaeologist who first turns one up. What remained at Kilcooly after that discovery was little more than the characteristic debris, the burnt and broken stones that are the signature of the type. No structural features or associated finds are recorded from the site.